Rotary Encoder Expermenter's Board: Improving the Hardware

Quick one this time....I have posted a few projects lately that incorporated a Raspberry Pi Pico, rotary encoder, and .96" OLED: here, here, and here. To make it unnecessary to breadboard the hardware, I posted an "experimenters board"--a development board to enhance a RP Pico that adds a rotary encoder, an OLED, a buffered GPIO output, and other enhancements.

Just now I updated the KICAD and Gerber files on the PCBWAY community site salient to the posts: go here.

The 9-29-24 revision of the experimenter's board uses less components, incorporates the encoder debounce library here, superseding the less responsive CD4011 based hardware debounce discussed here. 

Good news: it all works.

Thanks to Wendy and the gang and PCBWAY for patiently providing revised me with PCB's. You can help this blog by checking 'em out. 

9-29-24 revision

To make sure the grounding issues I saw with earlier revisions was a function the PCB's layout, not the schematic nor code, I breadboarded the entire "dev board for a dev board":

The breadboard example worked every time, but some of the older experimenters PCB's didn't, so, for versions of the board prior to 9-29-24, I felt I proved that this was a hardware/PCB layout issue.

I thought trace layouts for low frequency audio wasn't terribly important--put things almost anywhere, thrown in whatever traces you want--it will work--we are the bottom feeders?

Wrong. Apparently the I2C traces (at the very least) needed to be treated with forethought. probably any digital traces? 

Previously: more narrow traces....no ground pour

9-29-24 design improves that. 

I found myself putting the 9-29-24 assembly on hold for a couple of weeks, partially because I was tired of revising the board, and also having a feeling (incorrect, fortunately) that the 9-29-24 revisions would make things less reliable, not more.

Word of caution: 1306 128x64 .96 OLED's are everywhere but there appear to be 2 different pinouts coming from Shenzen: GND far left, and VCC far left.  

My design requires VCC on the far left--make sure you get that style of OLED if you build this project.

Spinning the rotary encoder advances or diminishes the counter on the OLED as expected. Every time, without fail. Thank goodness.  

Next: I have augment the code to create a user interface for the frequency counter....yes, I will get to that someday, but it means a lot of code changes.  

For now it's back to my day job--for better or worse the Pandemic is over.